If you are married, the first $500,000 of gain on your home is tax-free ($250,000 if you are single). Everything above that is taxed at up to 23.8% federally plus Massachusetts’ 5%. A large enough gain can also trigger the state’s 4% surtax and higher Medicare premiums two years later. For a longtime Newton or Wellesley owner whose house has tripled in value, the combined bill on a single sale can approach $300,000.
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I’m Nick Stevens, CFP®, founder of Evergreen Wealth Management in Boston. Many of the people I work with bought their homes in the 1990s for a fraction of today’s prices. They assume the home-sale exclusion covers them because it did for their parents. In the Boston suburbs it often doesn’t, and the time to figure that out is before you list the house, not when your CPA calls in March.
How does the home sale exclusion work?
You can exclude up to $250,000 of gain ($500,000 for a married couple filing jointly) if you owned the home and lived in it as your main residence for at least two of the five years before the sale. You can generally use the exclusion once every two years. The details are in IRS Publication 523 on selling your home.
Massachusetts follows the federal exclusion, so the gain you exclude federally is also excluded from state income. The problem is the cap. It has been $250,000 and $500,000 since 1997, and it has never been indexed for inflation. Home prices in towns like Newton, Wellesley, Lexington and Needham have not stood still for 29 years.
Why does the exclusion fall short in Newton and Wellesley?
Because a house bought for $450,000 in the mid-1990s can easily sell for $2 million or more today, and that creates a gain of well over $1 million. The exclusion covers less than half of it. Here is how the math looks at different gain levels for a married couple:
| Gain after basis and selling costs | Excluded (married) | Taxable gain |
|---|---|---|
| $400,000 | $400,000 | $0 |
| $800,000 | $500,000 | $300,000 |
| $1,200,000 | $500,000 | $700,000 |
| $1,600,000 | $500,000 | $1,100,000 |
A single seller, including a recently widowed spouse in some cases, only gets $250,000, so each row gets $250,000 worse.
What does the real tax bill look like?
Let’s walk through a realistic example. A retired couple bought their Newton colonial in 1996 for $450,000. Over the years they put $250,000 into documented improvements: an addition, a new kitchen, windows and a roof. In 2026 they sell for $2,400,000. They also have about $150,000 of other taxable income from pensions, IRA withdrawals and dividends.
- Sale price: $2,400,000
- Selling costs: about $136,000 (a 5% commission, the Massachusetts deed excise of $4.56 per $1,000 of sale price, and legal fees)
- Adjusted basis: $700,000 ($450,000 purchase price + $250,000 of improvements)
- Gain: about $1,564,000
- Taxable gain after the $500,000 exclusion: about $1,064,000
| Tax | How it applies | Approximate cost |
|---|---|---|
| Federal long-term capital gains | About $450,000 at 15%, the rest at 20% | $190,300 |
| Net investment income tax | 3.8% on the gain above the $250,000 MAGI threshold | $38,000 |
| Massachusetts income tax | 5% on the taxable gain | $53,200 |
| Massachusetts 4% surtax | 4% on income above the 2026 threshold of $1,107,750 | $4,300 |
| Total in the year of sale | about $286,000 | |
| Medicare IRMAA (two years later) | Both spouses pushed into the top bracket for one year | about $13,900 |
That comes to roughly $300,000 on a house they think of as their home, not an investment. The net investment income tax deserves special mention. Its thresholds of $200,000 (single) and $250,000 (married) are not indexed either, and the IRS confirms that the taxable portion of a home sale gain counts toward it. Only the excluded portion is protected.
How do the surtax and IRMAA come into it?
A one-time gain counts as income in the year of the sale, just like a salary. In Massachusetts, taxable income above $1,107,750 in 2026 picks up an extra 4%, which I cover in detail in our guide to the Massachusetts 4% millionaires tax. In the example above, the couple crosses that line by about $106,000. If they had also done a large Roth conversion that year, the surtax would have been several times larger.
Medicare is the delayed hit. Part B and Part D premiums are set using your income from two years earlier. For a married couple, income above $750,000 lands in the top bracket, where the 2026 Part B premium is $689.90 a month per person instead of the standard $202.90. The home sale is not a “life-changing event” that qualifies for an appeal, so the surcharge usually sticks for that year. If you are within a few years of 65, read how Medicare IRMAA brackets work before you set a closing date.
What counts toward your cost basis?
Anything that adds value, extends the home’s life or adapts it to a new use. Routine repairs do not count. Every dollar of basis you can document is a dollar that isn’t taxed, and at the top combined rates that dollar is worth about 33 cents.
| Adds to basis | Does not add to basis |
|---|---|
| Additions, finished basements, new garages | Painting and routine maintenance |
| Kitchen and bathroom remodels | Repairing a broken appliance |
| New roof, windows, siding, HVAC, septic | Fixing a leak or patching drywall |
| Landscaping, driveways, fencing, a pool | Improvements that were later torn out |
| Closing costs you paid when you bought | Homeowners insurance and property taxes |
In the Newton example, the $250,000 of improvements the couple could prove saved them about $82,000 in tax. Couples who have lost the receipts are often leaving that much on the table. Contractor invoices, permit records from the town building department, old bank statements and even dated photos can help rebuild the record.
Which mistakes do longtime homeowners miss?
A few rules catch people who have been in their homes for decades:
- Rolled-over gains from before 1997. Under the old rules, gain from selling a previous home could be deferred into the next one. That deferred gain lowered the basis of your current house, and it comes due now.
- Home office or rental use. Depreciation you claimed (or were entitled to claim) after May 6, 1997 can’t be excluded. It is taxed at up to 25% federally.
- The death of a spouse. A surviving spouse can still use the full $500,000 exclusion if the home sells within two years of the death. Because Massachusetts is not a community property state, only the deceased spouse’s half of a jointly owned home gets a stepped-up basis. After that two-year window, the survivor falls back to $250,000.
How can you reduce the tax before you sell?
Most of the savings come from planning the year of the sale, not from clever tricks. Here is what I look at with clients:
- Rebuild your basis now, while you can still find the records.
- Clear the rest of the calendar. Skip or shrink that year’s Roth conversions and take IRA withdrawals the year before or after instead. Every other dollar of income in the sale year is taxed at the highest rates you’ll face all decade.
- Use capital losses. Loss carryforwards, or losses harvested in your taxable account, offset the home gain dollar for dollar.
- Bunch charitable giving. If you give anyway, a large gift of appreciated stock to a donor-advised fund in the sale year gets deducted against your highest-taxed income.
- Weigh holding against selling. For an owner in their late 80s, keeping the home until death can erase the gain through a stepped-up basis. That has to be weighed against care needs, cash flow and Massachusetts estate tax.
A contrarian note: installment sales get mentioned a lot, but they rarely work for an ordinary home sale because the buyer’s lender pays you in full at closing. For most families, the real levers are the ones listed above.
Why does a flat fee matter for a decision like this?
A home sale is often the largest single transaction of someone’s retirement. The sale proceeds are also the easiest money for an advisor to gather. An advisor charging 1% of assets under management earns more once your $2 million of equity lands in the portfolio. That doesn’t make them dishonest, but it is a conflict worth knowing about when you’re deciding whether to sell, downsize or stay.
At Evergreen Wealth Management, we’re a fee-only fiduciary with a flat monthly fee, no matter how large your portfolio gets. Selling the house doesn’t change what we earn, so our job is simply to get the tax math right. You can see exactly how our flat-fee pricing works, how sale proceeds would fit into our investment management approach, and real client planning scenarios where timing mattered.
Frequently Asked Questions
Does Massachusetts tax capital gains on selling a home?
Yes, but only on the gain above the federal exclusion. Massachusetts follows the $250,000/$500,000 exclusion and taxes the remaining long-term gain at 5%. If your total taxable income tops $1,107,750 in 2026, the 4% surtax applies to the excess.
Can I avoid capital gains by buying another house?
Not anymore. The rule that let you roll gain into a replacement home ended in 1997. Buying a smaller or more expensive home afterward has no effect on the tax owed on the one you sold.
Do I need to pay estimated taxes after selling my home?
Often, yes. A large gain in a year with little withholding can lead to underpayment penalties both federally and in Massachusetts. Many people make an estimated payment in the quarter the sale closes.
Does Evergreen help plan the timing of a home sale?
Yes. Home sale planning is part of the tax planning included in our flat monthly fee. We model the sale in the context of your whole plan, including Roth conversions, IRMAA, the surtax and where the proceeds go, and coordinate with your CPA and real estate attorney.
The bottom line
The home-sale exclusion was designed for a housing market that no longer exists in the Boston suburbs. If you have lived in your home for decades, assume part of your gain will be taxed, and do the math before you sign a listing agreement. A year of planning can often save tens of thousands of dollars. If you’d like help modeling your sale, you can see what working with us looks like, or read more about me and how I work.
This article is for educational purposes only and is not tax or legal advice. Tax figures reflect 2026 rules and the example uses simplified assumptions. Please confirm the details of your own sale with a tax professional.
Nick Stevens, CFP® is the founder of Evergreen Wealth Management in Boston, a flat-fee financial planning and investment management firm. Evergreen charges a fixed monthly fee regardless of portfolio size. Learn more about how we work at our fee structure page or get in touch at our contact page.